In the past various types of protective devices have been used in vehicles to reduce injury to occupants during a crash event. In ground transportation vehicles, the protective devices started with lap belts, moved to lap/shoulder harnesses and then added inflatable systems where the inflatable device is stored in a fixed structure. For example, air bags used in automobiles are commonly stored in the steering wheels, instrument panels, side panels and roof rails. In aircraft, the protective devices started with lap belts and have recently introduced seat belt air bags, which have an inflatable member inside or on the seat belt. When deployed, the aircraft seat belt air bag device inflates an air bag into the area in front of the occupant wearing the seat belt. All air bag systems use a crash sensor that identifies a crash event and then activates a gas supply source. The most common automotive driver and passenger air bag systems have the gas source and bag storage co-located in the steering wheel or in the instrument panel. A gas delivery hose of substantially non-flexible construction is used when the gas storage is remote to the air bag storage such as in the aircraft air bag system.
The most common automotive driver and passenger air bag systems require redesigning the steering wheel or the passenger side instrument panel to install the air bag device. In ground vehicles, a seat belt air bag system does not require as much component redesign to install as they replace the seat belt and have the gas source mounted under the seat.
The present invention provides an inflatable bag vehicle safety system which can be conveniently installed in vehicles or aircraft. The system components are light and flexible and require minimal intrusion into driver/passenger space. Cost and installation times are minimized by virtue of the design simplicity of the system, particularly by reducing the number of hard fittings required.
A further improvement is the provision of a gas escape passage where the inflating gas is introduced into the inflatable bag, which escape passage can be accurately sized to control the rate of gas escape bag deflation after a crash event.
The present safety system utilizes a source of pressurized gas which is released to inflate a protective bag. The bag is contained within a suitable protective cover and is located on the lap belt portion of a restraining harness. The restraining harness can be either of the two or three point variety, as desired. A three point restraining system utilizes a shoulder strap whereas a two point system uses only a lap belt, all as well known in the art. When gas is released in response to sensing devices, it flows from the source of gas to the inflatable bag through a flat seamless flexible woven gas supply hose. This hose can be a polyester weave containing strands of kevlar for strengthening and can be coated internally with polyurethane. The use of this flat yet flexible hose saves space and also imparts a suppleness that enhances the user""s comfort, as compared to the round gas metal supply tubes used in prior art systems.
The inlet end of the supply hose is connected to the gas source by a standard plastic or metal fitting but the outlet end of the hose which is located in the inflatable safety bag has no fitting whatsoever. Specifically, the outlet end of the hose is positioned within the inflatable bag and secured to the bag but not to the underlying lap belt part. The lap belt part is in the preferred embodiment secured to the bag at a location other than where the hose is attached to the bag.